MIT researchers have a new breakthrough photovoltaic solar panel barrier that will allow more efficient solar panels than ever before.
The sun is just a massive ball of energy, spewing heat, light and radiation into the cosmos, so it seems like it should be easy for us to harness that and convert that energy to a form we can use. But a limitation in the technology behind photovoltaic solar panels only allows the renewable energy technology to collect, at most, about 34 percent of the sun’s energy that reaches Earth — until now.
The limit, the Shockley-Quiesser efficiency limit, describes a limit in how visible light can be converted into electricity, making photons release electrons. One photon releases one electron.
The MIT researchers, in a study published in Friday's Science journal, have now flown past that limit with a new technique that allows a single photon to release two electrons, effectively doubling the potential, which is massive for the typically slowly progressing field of photovoltaic solar panels. It may take awhile to get to that point, though, according to MIT professor and participating researcher Marc Baldo.
“While today’s commercial solar panels typically have an efficiency of at most 25 percent, a silicon solar cell harnessing singlet fission should make it feasible to achieve efficiency of more than 30 percent," Baldo says — "a huge leap in a field typically marked by slow, incremental progress," an MIT press release says. "In solar cell research," he notes, "people are striving ‘for an increase of a tenth of a percent.’ ”
The researchers are developing a new addition to go on top of existing photovoltaic solar panel technology to offer the boost.
“Solar panel efficiencies can also be improved by stacking different solar cells together, but combining solar cells is expensive with conventional solar-cell materials,” the release says. “The new technology instead promises to work as an inexpensive coating on solar cells."
The work made use of a known material, but the team is now exploring new materials that might perform the same trick even better.
"The field is working on materials that were chanced upon," Baldo says — but now that the principles are better understood, researchers can begin exploring possible alternatives in a more systematic way.
